Sucker rod shock absorber



Dec. 19, 1961 J. H. HOWELL ETAL 3,013,793

SUCKER ROD SHOCK ABSORBER 2 Sheets-Sheet 1 Filed July 24. 1959 4 J W T N m WM V A r mr r a 2 an an E Y 3 0e #4 a M a Dec. 19, 1961 J. H. HOWELL ETAL 3,013,793

SUCKER ROD suocx ABSORBER 2 Sheets-Sheet 2 Filed July 24, 1959 INVENTORJ 4464597- J-GAMLAJ, cLAeE/Vce' v. F/LLMAA/ 3,013,793 SUCKER ROD SHOCK ABSORBER Joe H. Howell, Box 292; Clarence'V. Fillman, Box 785; and Albert J. Gallas, Star Rte., all of Kermit, Tex. Filed July 24, 1959, Ser. No. 829,259 4 Claims. (Cl. 267-1) This invention relates to improvements in means for supporting sucker rods of oil well pumping equipment, and more particularly to a cushioned sucker rod joint adapted to operate as a shock absorber to smooth out the fluctuations of stress on the sucker rod of an oil Well pumping apparatus.

A main object of the invention is to provide a novel and improved cushioned sucker rod joint which is simple in construction, which involves relatively inexpensive components, and which greatly increases the useful life of the sucker rod and elements associated therewith in an oil well pump.

A further object of the invention is to provide an improved means for cushioning the impacts and other sudden stresses occurring in a sucker rod, for example, stresses due to fluid pounding such as that which occurs when the pump plunger strikes fluid on its down stroke, and to minimize the tendency for the sucker rod to whip or buckle inside the associated well tubing, whereby to reduce unnecessary wear on the tubing and on the associated well casing, said means being easy to install, being reliable in operation, and reducing the amount of power required to operate the pumping apparatus by smoothing out the power demands on the power source.

' Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a vertical cross sectional view showing a typical oil well pump having a sucker rod provided with cushioned rod joints constructed in accordance with the present invention.

FIGURES '2A, 2B and 2C are enlarged vertical cross sectional views showing successive segments of a cushioned sucker rod joint such as employed in the assembly of FIGURE 1.

FIGURE 3 is a horizontal cross sectional view taken on the line 3-3 of FIGURE 2B.

FIGURE 4 is a horizontal cross sectional view taken on the line 44 of FIGURE 2B.

FIGURE 5 is a horizontal cross sectional view taken on the line 55 of FIGURE 23.

FIGURE 6 is a horizontal cross sectional view taken on the line 66 of FIGURE 2B.

FIGURE 7 is a horizontal cross sectional view taken on the line 77 of FIGURE 2C.

FIGURE 8 is a horizontal cross sectional view taken on the line 8-8 of FIGURE 2C.

FIGURE 9 is a perspective .view of the piston member employed on the shank portion of the sucker rod'joint illustrated in FIGURES 2A, 2B and 2C.

Referring to the drawings, 10 generally designates an oil well pumping apparatus of generally conventional construction which includes the sucker rod :tubing mem- States gtgm ber 12 mounted in the well casing 13, the tubing member 12 containing the vertical sucker rod 14, the lower end of which is connected to the pump piston 15.

' In accordance with the present invention, the sucker rod 14 comprises a plurality of sections 16 which are connected together in succession by cushioned rod joint assemblies designated generally at 17. Each of the cushioned sucker rod joints 17 comprises a driving member 18 including anexternally threaded "top stud portion 19 adapted to be connected to the lower end portion of the sucker rod section 16 upwardly adjacent thereto and further including a vertical depending shank 20. The sucker rod joint 17 further includes a driven member 21 provided with a depending externally threaded stud portion 22 adapted to be rigidly connected'to' the top portion of the subjacent sucker rod section 16, the driven member 21 further including a vertical sleeve 23 which is threadedly engaged on the lower portion of the driven member 21, as shown at 24. Threadedly engaged in the top portion of the vertical sleeve 23- is a sleeve member 25 which slidably receives the shank 20, the sleeve member 25 being threadedly engaged in the sleeve member 23 at the threads 27. The sleeve member 25 is formed at its bottom edge with the annular rim 28 defining an abutment member.

Designated at 29 is a piston member which is rigidly secured to the intermediate portion of the shank 20, said piston member 29 being threadedly engaged on threads 30 formed on said intermediate portion of the shank and being rigidly secured to the shank by a plurality of set screws 31 threaded through the wall of the piston and clampingly engaged with the shank 20, as shown in FIG- URE 5. The piston member 29 is formed with the upper and lower annular grooves 32, 32 and with a plurality of vertical grooves 33 intersecting the annular grooves 32 and communicating with upper and lower fluid passages 34 provided on the piston member 29 above and below the grooves 32, providing passageways for fluid to flow freely along the piston member 29', whereby to equalize the fluid pressures above and below the piston members. Surrounding the shank 20 in the space above the piston member 29'is a series of alternating rigid and resilient ring members defining a first resilient force-transmitting assembly between the annular abutment element 28 and the top rim of the piston member 29. Thus, a metal ring member 35 surrounds the shank 20and is disposed immediately beneath the annular bottom rim 28 of sleeve 25. An alternating series of rubber rings 36 and metal rings 3-7 surround'the shank 20 below the ring 35, and an additional metal ring 38 surrounds shank 20 and is disposed beneath the lowermost rubber ring 36. As shown in FIGURE 2B, under normal conditions a small annular space 39 is provided between the metal ring 38 and the top rim of the piston member'29. This allows a small amount of free upward movement of the piston member 29 before it engages the resilient force-transmitting means defined by the series of rings 35, 36, 37 and 38.

As shown'in FIGURE 2B, the rings 36 and 37 are pref erably generally cylindrical and of substantial height, and are freely slidable with respect to the shank 20 The top and bottom rings 35 and 38 are also freely slidable with respect to the shank 20.

T'he driven member 21 is integrally formed with the upstanding sleeve portion 40 which is received within the main sleeve 23- and which terminates in the annular top rim 41, defining a force-receiving abutment means to rea ceive downward force from the piston 29. Disposed in the space between the bottom rim of piston 29 and the abutment rim 41 is a second series of alternating rigid and resilient rings defining a second resilient force-transmitting assembly. Thus, a metal ring 42 surrounds the shank 20 immediately subjacent the bottom rim of the piston 29. An alternating series of rubber and metal rings 43, 44 and 45 is disposed between the ring 42 and the top rim 41 of sleeve member 40. A normal clearance space 46 is provided between the uppermost ring'42 and the bottom rim of the piston 29 to allowa small amount offree movement of the piston 29 before it engages the resilientforce-transmitting assembly defined by "the rings 42, 4s, 44 and 45.

The bottom'end of the shank 20 is squared in cross section, as shown at 45, and is slidably received in a squared bore portion 49 formed in the bottom of the sleeve member 40, the squared shank element 48 being freely slidable but being non-rotatable in the square bore 49. Thus, the driving member 18 is held against rotation relative to the driven member 21 while being longitudinally movable relative thereto and being in forcetransmitting relationship therewith.

In operation, on the downward stroke of the sucker rod 14, each driven member receives downward force from the associated driving member 18, through the shank 20, the piston 29 and the resilient force-transmitting assembly comprising the alternating rigid and resilient rings 42, 43, 44 and 45, the downward force being applied to the abutment rim 41 of the sleeve member 40 formed integrally with the driven member. On the upward stroke, force is transmitted from the shank 20 through the top rim of the piston 29 to the resilient force-transmitting assembly comprising the alternating rigid and resilient rings 35, 36, 37 and 38, the force being applied to the annular abutment rim 28 of the sleeve element 25 associated with the sucker rod joint. The upward force is thus transmitted to the driven member 21 of the joint by the sleeve member 23 thereof. Thus, the cushioned joints 17 act to smooth out the fluctuations of loading on the sucker rod in both directions of movement thereof, and minimizes wear on the rod and the parts associated therewith, as well as reducing any tendency for the sucker rod to whip or buckle inside the tubing 12. Since loading on the sucker rod is smoothed out, the power demands on the source of power associated with the pump are reduced and made more nearly uniform.

While a specific embodiment of an improved sucker rod joint for an oil well pump has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

l. A cushioned sucker rod joint of the character described comprising a driving member including a vertical depending shank, a driven member including a vertical sleeve receiving said shank, a piston element secured to said shank and slidably engaging the inside surface of the sleeve, such shank extending a substantial distance below said piston element, an annular abutment member secured to the upper portion of said sleeve and substantially slidably surrounding said shank, annular abutment shoulder means in the sleeve on the driven member, surrounding said shank and located below said piston element, first resilient force-transmitting means surrounding said shank in the space between said piston element and said annular abutment member, and second resilient forcetransmitting means surrounding said shank in the space between said piston element and said annular abutment shoulder means, said shank having a portion of nou circular cross section and said sleeve having a noncircular bore portion slidably and non-rotatively receiving said non-circular shank portion.

2. A cushioned sucker rod joint of the character described comprising a driving member including a vertical depending shank, a driven member including a vertical sleeve receiving said shank, a piston element secured to said shank and slidably engaging the inside surface of said sleeve, said shank extending a substantial distance below said piston element, an annular abutment member secured to the upper portion of said sleeve and substantially slidably surrounding said shank, annular abutment shoulder means in the sleeve on the driven member, surrounding said shank and located below said piston element, a first series of alternating rigid and resilient ring members defining first resilient force-transmitting means surrounding said shank in the space between said piston element and said annular abutment member, and a second series of alternating rigid and resilient ring members defining second resilient force-transmitting means surrounding said shank in the space between said piston ele ment and said annular abutment shoulder means, said shank having a portion of non-circular cross section and said sleeve having a non-circular bore portion slidably and non-rotatively receiving said non-circular shank portion.

3. A cushioned sucker rod joint of the character described comprising a driving member including a vertical depending shank, a driven member including a vertical sleeve receiving said shank, a piston element secured to said shank and slidably engaging the inside surface of said sleeve, said shank extending a substantial distance below said piston element, an annular abutment sleeve member threadedly engaged in the upper portion of said sleeve and substantially slidably surrounding said shank, an upstanding annular abutment sleeve member integrally formed on the driven member and extending upwardly in the first-named sleeve below said piston element and surrounding said shank, a first series of alternating rigid and resilient ring members defining first resilient forcetransmitting means surrounding said shank in the space between said piston element and said threadedly engaged sleeve member, and a second series of alternating rigid and resilient ring members defining second resilient forcetransmitting means surrounding said shank in the space between said piston element and said last-named sleeve member, said shank having a portion of non-circular cross section and said sleeve having a non-circular bore portion slidably and non-rotatively receiving said noncircular shank portion.

4. A cushioned sucker rod joint of the character described comprising a driving member including a vertical depending shank, a driven member including a vertical sleeve receiving said shank, a piston element secured to said shank and slidably engaging the inside surface of said sleeve, said shank extending a substantial distance below said piston element, an annular sleeve member threadedly engaged in the upper portion of said first-named sleeve and substantially slidably surrounding said shank, an upstanding annular abutment sleeve member integrally formed on the driven member and extending upwardly in the first-named sleeve below said piston element and surrounding said shank, a first series of alternating rigid and resilient ring members defining first resilient forcetransmitting means surrounding said shank in the space between said piston element and said threadedly engaged sleeve member, and a second series of alternating rigid and resilient ring members defining second resilient forcetransmitting means surrounding said shank in the space between said piston element and said last-named sleeve member, the lower end portion of said shank being noncircular in cross section and said last-named sleeve member being formed with a non-circular bore portion of similar shape to and slidably receiving said non-circular lower end portion of said shank, substantially preventing rotation of said driven member with respect to said driving member.

References Cited in the file of this patent UNITED STATES PATENTS 873,092 Rommel Dec. 10, 1907 1,785,559 Ponti Dec. 16, 1930 1,788,363 Brooks et al. Ian. 6, 1931 2,212,153 Eaton et al. Aug. 20, 1940 2,230,029 Eaton Jan. 28, 1941 2,240,519 Reed May 6, 1941 2,400,941 McFarlane May 28, 1946 2,620,165 Crickmer Dec. 2, 1952 2,671,682 Page Mar. 9, 1954 

